I think if you took the time to learn them you'd find that the interpretations of the Torah they contain are vastly different from what you were taught. The Koran teaches that the Torah has been corrupted over time and it contains God's corrections to it. The NT reinterprets the Torah in light of Jesus being the messiah. I'm not saying they are right and you are wrong but I am saying that, in their eyes, your claim of authority simply displays the fact that you haven't studied Scripture.Since the NT and the Koran contain verses that admit they were copied from the Torah (I understand no one went of their way to alert you to this fact), I think I can make my statement with a certain amount of authority.Of course you mean they haven't studied your Scripture. Have you studied all the others?There is nothing new under the sun.
Every jerk who comes up with another twist on the, "There's no God", simply displays the fact that they haven't studied Scripture.